The products seek to provide inverse exposure to VIX short-term futures and, when that measure spikes, the investment loses value, at which time ETP issuers could liquidate the shares.

It was not immediately clear if the issuers would opt to liquidate these products.

BlackRock did not mention the products by name, but reiterated its long-held view that inverse and “leveraged” ETPs that double or triple market returns “are not ETFs, and they don’t perform like ETFs under stress,” adding “that’s why iShares does not offer them.”

IShares is the brand name for BlackRock’s exchange-traded funds (ETFs).

BlackRock also called for a regulatory classification system to label levered and inverse ETPs differently than plain-vanilla ETFs, to show the risks associated with such products.

SVXY sponsor ProShare Capital Management LLC declined to comment. Janus Henderson Group plc, which markets the VelocityShares notes, could not be reached immediately.

“The XIV ETN activity is reflective of today’s market volatility. There is no material impact to Credit Suisse,” said spokeswoman Nicole Sharp. She declined to comment further.

Stocks plummeted in highly volatile trading on Monday, with the benchmark S&P 500 index and the Dow Jones Industrials suffering their biggest respective percentage drops since August 2011 as a long-awaited pullback from record highs deepened.

For the Dow, the fall at one point of nearly 1,600 points was the biggest intraday point loss in Wall Street history.

Reporting by Trevor Hunnicutt in New York and additional reporting by Ismail Shakil in Bengaluru; Editing by Gopakumar Warrier